1. Field of the Invention
The present invention relates to an imaging lens and an electronic apparatus including the same.
2. Description of the Related Art
In recent years, as use of portable electronic devices (e.g., mobile phones and digital cameras) becomes ubiquitous, much effort has been put into reducing dimensions of portable electronic devices. Moreover, as dimensions of charged coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) based optical sensors are reduced, dimensions of imaging lenses for use with the optical sensors must be correspondingly reduced without significantly compromising optical performance.
Each of U.S. Pat. Nos. 7,480,105, 7,639,432, 7,486,449 and 7,684,127 discloses a conventional imaging lens with five lens elements. In each of U.S. Pat. Nos. 7,480,105 and 7,639,432, a first lens element thereof has a negative refractive power, and a second lens element thereof has a positive refractive power. In each of U.S. Pat. Nos. 7,486,449 and 7,684,127, each of first and second lens elements thereof has a negative refractive power. However, such arrangements of the refractive power of the lens elements do not lead to good optical characteristics, and each of the imaging lenses disclosed in the abovementioned patents has a system length ranging from 10 mm to 18 mm, failing to reduce an overall length for application to portable devices.
Each of U.S. Pat. Nos. 8,233,224, 8,363,337 and 8,000,030 also discloses a conventional imaging lens with five lens elements, including a first lens element with a positive refractive power and a second lens element with a negative refractive power. While such arrangement of the refractive power of the lens elements may be relatively good, since surface designs of third, fourth and fifth lens elements in these two patents fail to reduce the length of the imaging lens and improve image abbreviation at the same time, the overall length of the imaging lens is not sufficiently reduced in consideration of the image quality. For example, some of the imaging lenses have an overall length of about 6.0 mm, which may need further improvement.
Reducing the system length of the imaging lens while maintaining sufficient optical performance is always a goal in the industry.